vems not generating spark - it was working fine

[alev8]

hi guys
my vems for audi aan pnp stopped working

it was working perfectly .
i started it this morning but it stalled. then i tried again and got this no spark situation


i really dont know what to look for. the ecu itself is working, i can connect to it using bluetooth .
the fuel pump primes.
the fuel inectors are injecting... just the spark is missing, i´ve re uploaded a map and it is the same
can anyone help me with this?
i am using the coil conversion from 034 . i tested all 5 coils and none are generating spark

[alev8]

i tested now and even i am not having any trigger erros, the car isnt seeing rpm on the start up

i also testes the coils using vems test and a spark tester and it is fine
can this be a vems problem or any sensor related? (g40 for example)

[afterthought]

Which Car is this in?
Reason for asking is in the stock AAN harness the engine needs to see RPM before triggering fuel and spark I think.
Is it AAN PNP ecu mated to a engine stock harness?

[alev8]

Hi
Yes, it is a stock aan
usr 6 aan. vems model is a pnp for aan also

the car has more then 10.000 miles on vems already. was working flawlessly

i did a trigger log .
uploaded to vems sharing central
http://vems.hu/vemstune/sharingcente...iew&key=CLzXAi

[afterthought]

A couple quick easy things to check
Do you have any codes?
Is it possible the grounds are loose for the ignition system?
Fuse S64 the fuse for the ignition, is that OK
Im trying to remember how to check if VEMS is outputting a spark signal.
did you check your timing marks are lined up?

[alev8]

Cool
the timing marks are lined.

i tested the ignition using vems test mode and saw spark when on test mode.

the fuses are ok, s 64 and s72

the problem appears to be that vems is not seeing any rpm when o crank the engine.

dont know if this is something related to g40, g28 and g4.
or is it something wrong with my vems ecu...

[afterthought]

I was trying to think through that.... The stock AAN fuel pump system does not give you fuel until it sees RPM I thought. So it must be seeing a signal somewhere.

[afterthought]

It's possible that it is internal , I dont know much about the inner workings of the ecu.
Have another ECU you could try by chance?

Pin 40/55 is the G28 output to the cluster and stuff
Pin 49/55 Input from G28
Pin 48/55 is two wires a shared ground for G4 and G28

I think you can test the RPM sensor , but I think the car is seeing RPM in order to trigger thefuel pump

[alev8]

yes, i can hear the pump prime it self but i am not hearing it working during crank.
on further verification, the fuel injectors arent injecting.

i checked vems manual and to make a fuel injector inject, vems need a rpm signal which on my case it is not getting.

[alev8]

the fuel pump is just priming itself. i checked vems log and no rpm signal.

i dont have another ecu on hand to test...
i can get one later just for testing. i also can get a original motronic just to see if the car starts...

[alev8]

i guess i found out the problem
currently my car is using , on vems, the secondary trigger as cam sync.

when i disabled it , the car started.
so i guess the problem is the g40 sensor

any thoughs?

[afterthought]

I have never personally had one go bad other than my connector broke and left me with just 3 pins... Could check your connnections (that plug is subject to alot of heat up there) and test continuity on the wires to be sure .
I would suspect the sensor myself but being that all my cars are 20+ years old I always check the wiring too, and the pins at the ECU can be bent too from removal or install.
You could test the sensor itself by using the legs if a cheap LED stabbed into the connector or *i think* with a multimeter

[alev8]

Hey guys
Just to share info

I changed the g40 and the car is working fine .

Don't konw what happened... The sensor was showing some wear and the wires were soldered already by me two years ago. Now even though the wires are fine the sensor wasn't working as expected.

[afterthought]

Dang good deal.
Did you have to remove the crank pulley to change that?

[Billman]

I had issues on the past with Motronic and the camshaft hall sensor.